Since 1852, Smith & Wesson has been associated with high-performance and high-precision firearms. To maintain efficient production speeds and keep up with customer demand, the company’s manufacturing processes use approximately 30,000 gal. of machine lube oil per year, of which 19,800 gal. is recycled.
Smith & Wesson contracted with an outside service to filter, clean and dry the oil. The oil processing and recycling program required the company to accumulate and store 1,500 gal. of used oil every two months. The mobile processor treated the oil at a cost of $4,375 per month. The total annual cost of this program was $52,500, a lower cost per gallon than oil replacement at $6 to $8 per gal. for mineral oil and as much as $60 per gal. for synthetic oils. However, the significant expenses and inconvenience led Smith & Wesson to pursue a new oil conditioning solution.
MSC Filtration Technologies (www.mscliquidfiltration.com), a distributor for Pentair Industrial (www.pentairindustrial.com), introduced Smith & Wesson to the Driflex oil conditioning system, marking the beginning of a fast-tracked project with Henkel Chemical Management (www.henkelna.com) to evaluate the system.
The Driflex system removes free, emulsified, and dissolved water from oil in batches of any size. The system initially appealed to Smith & Wesson from a convenience standpoint; it would allow the company to process oil in its own facility, on its own schedule, and in any volume it wanted.
Contaminated oil flows through a particulate filter, a membrane filter, and an air dryer to remove metal particles and moisture.
In addition, keeping the oil processing in-house eliminates the costs of clean-up services associated with off-site processors or third-party, truck-mounted vacuum dehydrator systems. Not only did clean-up services cost tens of thousands of dollars, but they also carried the risk that the oil would be permanently damaged and lost during the clean-up process. Along with eliminating this risk and additional cost, the system promised to improve overall oil quality.
The Driflex oil conditioning system couples Pentair’s patented UltiDri membrane technology with high-efficiency filtration to cost-effectively remove known, harmful contaminants from lubrication and hydraulic fluids. The system operates by flowing contaminated oil through a particulate filter, a membrane filter, and an air dryer. The result: both particulate and moisture are removed from the oil, and the oil is restored for reuse.
Smith & Wesson processes lube oil in 250-gal. to 300-gal. totes, replacing two to three totes (500 gal. to 900 gal.) of oil per week. The company selected a 4 gpm Driflex to meet the volume and processing time requirements. A system of this size is capable of processing the company’s typical weekly oil volume within a few days, with no outside schedules to accommodate or third-party expenses to pay.
Unfiltered oil quality varies depending upon how many times it’s already been recycled, as well as how much particulate and moisture it accumulated during its service life. Smith & Wesson’s unfiltered oil presented a significant challenge, as it contained a fairly heavy load of fine metal and grinding dust: 350 mg/L, with particles ranging in size from 2 to 10 microns. This contamination prevented the Driflex system from providing optimum oil conditioning. To handle this type of contamination, a duplex, prefiltration housing unit (Pentair Industrial Model #H8836) containing 5-micron Triflex Mega Cartridges treats the oil before it enters the Driflex system. This cartridge prefiltration system removes the fine particulates before oil conditioning takes place, allowing the Driflex unit to remove moisture more effectively.
Another difficulty arose when a process accident during the test period introduced a great deal of water to the unfiltered oil. After this incident, the oil’s moisture content registered at 2%, which is 20 times higher than normal. The Driflex system still delivered results, but took several additional days to process the oil. The oil was continuously recirculated until the desired level of dryness was achieved without interruption to Smith & Wesson’s operation or oil quality.
Smith & Wesson enjoys a significant reduction in its oil processing and recycling costs. After purchasing the Driflex system, the company received a return on their investment in only two months. The savings continue, as the system’s annual operating cost is $4,500 compared to the $52,500 spent on an outside service.
An additional benefit is the ability to recycle smaller batches of oil. Small batches were often discarded, as it was cost-prohibitive to try to accumulate enough oil from these batches to warrant outside processing. Smith & Wesson can now process and reuse oil in batches of all sizes, with no valuable resources going to waste.
Pentair wishes to acknowledge Smith & Wesson as well as Henkel Chemical Management for their willingness to share specific operational and cost details, which made this success story possible.